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Li Z, Zhang S, Zuber F, Altenried S, Jaklenec A, Langer R, Ren Q. Topical application of Lactobacilli successfully eradicates Pseudomonas aeruginosa biofilms and promotes wound healing in chronic wounds. Microbes Infect 2023; 25:105176. [PMID: 37406851 DOI: 10.1016/j.micinf.2023.105176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/18/2023] [Accepted: 06/22/2023] [Indexed: 07/07/2023]
Abstract
Chronic wounds are difficult to treat due to the presence of biofilm which prevents wound healing. Pseudomonas aeruginosa is one of the most common pathogens found in chronic wounds and conventional treatment strategies have been ineffective in the eradication of its biofilm, without harming the surrounding healthy tissue at the same time. Here, we introduced an innovative approach applying the probiotic product Bio-K+ (containing three lactobacilli) topically as an antimicrobial and antibiofilm agent. We identified lactic acid as the main active component. While antibiotics and antiseptics such as silver-ions only demonstrated limited efficacy, Bio-K+ was able to completely eradicate mature P. aeruginosa biofilms established in an in-vitro and ex-vivo human skin model. Furthermore, it demonstrated biocompatibility in the co-culture with human dermal fibroblasts and accelerated the migration of fibroblasts in a cell migration assay promoting wound healing. To enhance clinical practicability, we introduced Bio-K+ into the hydrocolloid dressing Aquacel, achieving sustained release of lactic acid and biofilm eradication. This new treatment approach applying probiotics could represent a major improvement in the management of chronic wounds and can be extended in treating other biofilm-associated infections.
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Affiliation(s)
- Zhihao Li
- Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
| | - Sixuan Zhang
- Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Flavia Zuber
- Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Stefanie Altenried
- Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Ana Jaklenec
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA 02139, USA
| | - Robert Langer
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA 02139, USA
| | - Qun Ren
- Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
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2
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Kummer N, Huguenin-Elie L, Zeller A, Chandorkar Y, Schoeller J, Zuber F, Ren Q, Sinha A, De France K, Fischer P, Campioni S, Nyström G. 2D foam film coating of antimicrobial lysozyme amyloid fibrils onto cellulose nanopapers. Nanoscale Adv 2023; 5:5276-5285. [PMID: 37767031 PMCID: PMC10521212 DOI: 10.1039/d3na00370a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023]
Abstract
Amyloid fibrils made from inexpensive hen egg white lysozyme (HEWL) are bio-based, bio-degradable and bio-compatible colloids with broad-spectrum antimicrobial activity, making them an attractive alternative to existing small-molecule antibiotics. Their surface activity leads to the formation of 2D foam films within a loop, similar to soap films when blowing bubbles. The stability of the foam was optimized by screening concentration and pH, which also revealed that the HEWL amyloid foams were actually stabilized by unconverted peptides unable to undergo amyloid self-assembly rather than the fibrils themselves. The 2D foam film was successfully deposited on different substrates to produce a homogenous coating layer with a thickness of roughly 30 nm. This was thick enough to shield the negative charge of dry cellulose nanopaper substrates, leading to a positively charged HEWL amyloid coating. The coating exhibited a broad-spectrum antimicrobial effect based on the interactions with the negatively charged cell walls and membranes of clinically relevant pathogens (Staphylococcus aureus, Escherichia coli and Candida albicans). The coating method presented here offers an alternative to existing techniques, such as dip and spray coating, in particular when optimized for continuous production. Based on the facile preparation and broad spectrum antimicrobial performance, we anticipate that these biohybrid materials could potentially be used in the biomedical sector as wound dressings.
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Affiliation(s)
- Nico Kummer
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129, 8600 Dübendorf Switzerland
- Institute of Food Nutrition and Health, ETH Zurich Schmelzbergstrasse 9 8092 Zurich Switzerland
| | - Luc Huguenin-Elie
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129, 8600 Dübendorf Switzerland
| | - Adrian Zeller
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129, 8600 Dübendorf Switzerland
| | - Yashoda Chandorkar
- Laboratory for Biointerfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
| | - Jean Schoeller
- Laboratory for Biomimetic Membranes and Textiles, Empa - Swiss Federal Laboratories for Materials Science and Technology Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
- Institute for Biomechanics, ETH Zürich Stefano-Franscini-Platz 5 8093 Zürich Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
| | - Ashutosh Sinha
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129, 8600 Dübendorf Switzerland
- Institute of Food Nutrition and Health, ETH Zurich Schmelzbergstrasse 9 8092 Zurich Switzerland
| | - Kevin De France
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129, 8600 Dübendorf Switzerland
| | - Peter Fischer
- Institute of Food Nutrition and Health, ETH Zurich Schmelzbergstrasse 9 8092 Zurich Switzerland
| | - Silvia Campioni
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129, 8600 Dübendorf Switzerland
| | - Gustav Nyström
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129, 8600 Dübendorf Switzerland
- Institute of Food Nutrition and Health, ETH Zurich Schmelzbergstrasse 9 8092 Zurich Switzerland
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3
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Straub H, Zuber F, Eberl L, Maniura-Weber K, Ren Q. In Situ Investigation of Pseudomonas aeruginosa Biofilm Development: Interplay between Flow, Growth Medium, and Mechanical Properties of Substrate. ACS Appl Mater Interfaces 2023; 15:2781-2791. [PMID: 36601891 DOI: 10.1021/acsami.2c20693] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
To better understand the impact of biomaterial mechanical properties and growth medium on bacterial adhesion and biofilm formation under flow, we investigated the biofilm formation ability of Pseudomonas aeruginosa in different media on polydimethylsiloxane (PDMS) of different stiffness in real time using a microfluidic platform. P. aeruginosa colonization was recorded with optical microscopy and automated image analysis. The bacterial intracellular level of cyclic diguanylate (c-di-GMP), which regulates biofilm formation, was monitored using the transcription of the putative adhesin gene (cdrA) as a proxy. Contrary to the previous supposition, we revealed that PDMS material stiffness within the tested range has negligible impact on biofilm development and biofilm structures, whereas culture media not only influence the kinetics of biofilm development but also affect the biofilm morphology and structure dramatically. Interestingly, magnesium rather than previously reported calcium was identified here to play a decisive role in the formation of dense P. aeruginosa aggregates and high levels of c-di-GMP. These results demonstrate that although short-term adhesion assays bring valuable insight into bacterial and material interactions, long-term evaluations are essential to better predict overall biofilm outcome. The microfluidic system developed here presents a valuable application potential for studying biofilm development in situ. .
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Affiliation(s)
- Hervé Straub
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Department of Plant and Microbial Biology, University of Zürich, Zürich CH-8008, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zürich, Zürich CH-8008, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
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Guo F, Pan F, Zhang W, Liu T, Zuber F, Zhang X, Yu Y, Zhang R, Niederberger M, Ren Q. Robust Antibacterial Activity of Xanthan-Gum-Stabilized and Patterned CeO 2-x-TiO 2 Antifog Films. ACS Appl Mater Interfaces 2022; 14:44158-44172. [PMID: 36150021 DOI: 10.1021/acsami.2c11968] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Increased occurrence of antimicrobial resistance leads to a huge burden on patients, the healthcare system, and society worldwide. Developing antimicrobial materials through doping rare-earth elements is a new strategy to overcome this challenge. To this end, we design antibacterial films containing CeO2-x-TiO2, xanthan gum, poly(acrylic acid), and hyaluronic acid. CeO2-x-TiO2 inks are additionally integrated into a hexagonal grid for prominent transparency. Such design yields not only an antibacterial efficacy of ∼100% toward Staphylococcus aureus and Escherichia coli but also excellent antifog performance for 72 h in a 100% humidity atmosphere. Moreover, FluidFM is employed to understand the interaction in-depth between bacteria and materials. We further reveal that reactive oxygen species (ROS) are crucial for the bactericidal activity of E. coli through fluorescent spectroscopic analysis and SEM imaging. We meanwhile confirm that Ce3+ ions are involved in the stripping phosphate groups, damaging the cell membrane of S. aureus. Therefore, the hexagonal mesh and xanthan-gum cross-linking chains act as a reservoir for ROS and Ce3+ ions, realizing a long-lasting antibacterial function. We hence develop an antibacterial and antifog dual-functional material that has the potential for a broad application in display devices, medical devices, food packaging, and wearable electronics.
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Affiliation(s)
- Fangwei Guo
- Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai Key Laboratory of Spacecraft Mechanism, Shanghai 201108, China
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Fei Pan
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Wenchen Zhang
- Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tian Liu
- Shanghai Key Laboratory of Spacecraft Mechanism, Shanghai 201108, China
| | - Flavia Zuber
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Xing Zhang
- Shanghai Institute of Aerospace System Engineering, Shanghai 201108, China
| | - Yali Yu
- Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ruiji Zhang
- Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Markus Niederberger
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
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Pan F, Giovannini G, Zhang S, Altenried S, Zuber F, Chen Q, Boesel LF, Ren Q. pH-responsive silica nanoparticles for the treatment of skin wound infections. Acta Biomater 2022; 145:172-184. [PMID: 35417797 DOI: 10.1016/j.actbio.2022.04.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/15/2022] [Accepted: 04/06/2022] [Indexed: 12/20/2022]
Abstract
Chronic wounds are not only a burden for patients but also challenging for clinic treatment due to biofilm formation. Here, we utilized the phenomenon that chronic wounds possess an elevated local pH of 8.9 and developed pH-sensitive silica nanoparticles (SiNPs) to achieve a targeted drug release on alkaline wounds and optimized drug utility. Chlorhexidine (CHX), a disinfectant and antiseptic, was loaded into SiNPs as the model drug. The loaded CHX displayed a release 4 - 5 fold higher at pH 8.0 and 8.5 than at pH 6.5, 7.0 and 7.4. CHX-SiNPs furthermore exhibited a distinctive antibacterial activity at pH 8.0 and 8.5 against both Gram-negative and -positive bacterial pathogens, while no cytotoxicity was found according to cell viability analysis. The CHX-SiNPs were further formulated into alginate hydrogels to allow ease of use. The antibacterial efficacy of CHX-SiNPs was then studied with artificial wounds on ex vivo human skin. Treatment with CHX-SiNPs enabled nearly a 4-lg reduction of the viable bacterial cells, and the alginate formulated CHX-SiNPs led to almost a 3-lg reduction compared to the negative controls. The obtained results demonstrated that CHX-SiNPs are capable of efficient pH-triggered drug release, leading to high antibacterial efficacy. Moreover, CHX-SiNPs enlighten clinic potential towards the treatment of chronic wound infections. STATEMENT OF SIGNIFICANCE: A platform for controlled drug release at a relatively high pH value i.e., over 8, was established by tuning the physical structures of silica nanoparticles (SiNPs). Incorporation of chlorhexidine, an antimicrobial agent, into the fabricated SiNPs allowed a distinctive inhibition of bacterial growth at alkaline pHs, but not at acidic pHs. The efficacy of the SiNPs loaded with chlorhexidine in treating wound infections was further validated by utilizing ex vivo human skin samples. The presented work demonstrates clinic potential of employing alkaline pH as a non-invasive stimulus to achieve on-demand delivery of antimicrobials through SiNPs, showcasing a valuable approach to treating bacterial infections on chronic wounds.
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Pan F, Zhang S, Altenried S, Zuber F, Chen Q, Ren Q. Advanced antifouling and antibacterial hydrogels enabled by the controlled thermo-responses of a biocompatible polymer composite. Biomater Sci 2022; 10:6146-6159. [DOI: 10.1039/d2bm01244h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To optimally apply antibiotics and antimicrobials, smart wound dressing conferring controlled drug release and preventing adhesions of biological objects is advantageous. Poly(N-isopropylacrylamide) (PNIPAAm), conventional thermo-responsive polymer, and poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC),...
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7
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Kummer N, Wu T, De France KJ, Zuber F, Ren Q, Fischer P, Campioni S, Nyström G. Self-Assembly Pathways and Antimicrobial Properties of Lysozyme in Different Aggregation States. Biomacromolecules 2021; 22:4327-4336. [PMID: 34533934 DOI: 10.1021/acs.biomac.1c00870] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Antimicrobial resistance in microorganisms will cause millions of deaths and pose a vast burden on health systems; therefore, alternatives to existing small-molecule antibiotics have to be developed. Lysozyme is an antimicrobial enzyme and has broad-spectrum antimicrobial activity in different aggregated forms. Here, we propose a reductive pathway to obtain colloidally stable amyloid-like worm-shaped lysozyme nanoparticles (worms) from hen egg white lysozyme (HEWL) and compare them to amyloid fibrils made in an acid hydrolysis pathway. The aggregation of HEWL into worms follows strongly pH-dependent kinetics and induces a structural transition from α-helices to β-sheets. Both HEWL worms and amyloid fibrils show broad-spectrum antimicrobial activity against the bacteria Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and the fungus Candida albicans. The colloidal stability of the worms allows the determination of minimum inhibitory concentrations, which are lower than that for native HEWL in the case of S. aureus. Overall, amyloid fibrils have the strongest antimicrobial effect, likely due to the increased positive charge compared to native HEWL. The structural and functional characterizations of HEWL worms and amyloids investigated herein are critical for understanding the detailed mechanisms of antimicrobial activity and opens up new avenues for the design of broad-spectrum antimicrobial materials for use in various applications.
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Affiliation(s)
- Nico Kummer
- Laboratory for Cellulose & Wood Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.,Institute of Food Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich, Switzerland
| | - Tingting Wu
- Laboratory for Cellulose & Wood Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.,State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, 201620 Shanghai, P. R. China
| | - Kevin J De France
- Laboratory for Cellulose & Wood Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa-Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa-Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Peter Fischer
- Institute of Food Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich, Switzerland
| | - Silvia Campioni
- Laboratory for Cellulose & Wood Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland
| | - Gustav Nyström
- Laboratory for Cellulose & Wood Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.,Institute of Food Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich, Switzerland
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Pan F, Altenried S, Zuber F, Wagner RS, Su YH, Rottmar M, Maniura-Weber K, Ren Q. Photo-activated titanium surface confers time dependent bactericidal activity towards Gram positive and negative bacteria. Colloids Surf B Biointerfaces 2021; 206:111940. [PMID: 34265541 DOI: 10.1016/j.colsurfb.2021.111940] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/09/2021] [Accepted: 06/22/2021] [Indexed: 12/14/2022]
Abstract
Titanium (Ti)-based implants are broadly applied in the medical field, but their related infections can lead to implant failure. Photo-irradiation of metal materials to generate antimicrobial agents, an alternative to antibiotics, is a promising method to reduce bacterial infection and antibiotic usage. It is therefore important to understand how bacterial pathogens respond to Ti surfaces. Here, Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus, the most prevalent pathogens linked to healthcare-associated infections, were used as model strains. Two different kinds of Ti surfaces respectively stored in dry condition and 0.9 % NaCl solution were applied. Upon UV irradiation and in the absence of bacteria, both tested surfaces exhibited similar bactericidal activity, even though the surfaces stored in 0.9 % NaCl solution generated a slightly higher level of reactive oxygen species (ROS). Interestingly, P. aeruginosa and S. aureus responded to the irradiated Ti surfaces differently regarding interaction time: the number of viable P. aeruginosa was reduced up to 90 % after 30 min interaction with the treated surfaces compared to the untreated ones, but this reduction is lessened to 69 %-81 % after 240 min. By contrast, UV treatment of surfaces did not impact the viability of S. aureus after 30 min interaction, however, led to more than 99 % reduction after 240 min incubation. These results provide first experimental evidence that Gram negative and positive bacterial species respond to ROS with different inactivation kinetics. This work also demonstrated that treatment with photo-irradiation in the absence of bacteria conferred Ti surfaces with efficient bactericidal activity.
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Affiliation(s)
- Fei Pan
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Stefanie Altenried
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Raphael S Wagner
- Institut Straumann AG, Peter Merian-Weg 12, 4052 Basel, Switzerland
| | - Yen-Hsun Su
- Department of Materials Science and Engineering, National Cheng Kung University, University Road 1, Tainan 70101, Taiwan
| | - Markus Rottmar
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
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Pan F, Amarjargal A, Altenried S, Liu M, Zuber F, Zeng Z, Rossi RM, Maniura-Weber K, Ren Q. Bioresponsive Hybrid Nanofibers Enable Controlled Drug Delivery through Glass Transition Switching at Physiological Temperature. ACS Appl Bio Mater 2021; 4:4271-4279. [PMID: 35006839 DOI: 10.1021/acsabm.1c00099] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To avoid excessive usage of antibiotics and antimicrobial agents, smart wound dressings permitting controlled drug release for treatment of bacterial infections are highly desired. In search of a sensitive stimulus to activate drug release under physiological conditions, we found that the glass transition temperature (Tg) of a polymer or polymer blend can be an ideal parameter because a thermal stimulus can regulate drug release at the physiological temperature of 37 °C. A well-tuned Tg for a controlled drug release from fibers at 37 °C was achieved by varying the blending ratio of Eudragit® RS 100 and poly(methyl methacrylate). Octenidine, an antimicrobial agent often used in wound treatment, was encapsulated into the polymer blend during the electrospinning process and evaluated for its controlled release based on modulation of temperature. The thermal switch of the nanofibrous membranes can be turned "on" at physiological temperature (37 °C) and "off" at room temperature (25 °C), conferring a controlled release of octenidine. It was found that octenidine can be released in an amount at least 8.5 times higher (25 mg·L-1) during the "on" stage compared to the "off" stage after 24 h, which was regulated by the wet Tg (34.8-36.5 °C). The "on"/"off" switch for controlled drug release can moreover be repeated at least 5 times. Furthermore, the fabricated nanofibrous membranes displayed a distinctive antibacterial activity, causing a log3 reduction of the viable cells for both Gram negative and positive pathogens at 37 °C, when the thermal switch was "on". This study forms the groundwork for a treatment concept where no external stimulus is needed for the release of antimicrobials at physiological conditions, and will help reduce the overuse of antibiotics by allowing controlled drug release.
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Affiliation(s)
- Fei Pan
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biointerfaces, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Altangerel Amarjargal
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.,Power Engineering School, Mongolian University of Science and Technology, Baga Toiruu 34, 14191 Ulaanbaatar, Mongolia
| | - Stefanie Altenried
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biointerfaces, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Mengdi Liu
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biointerfaces, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.,Department of Earth- and Environmental Sciences, Ludwig Maximilian University of Munich, Theresienstrasse 41, 80333 Munich, Germany
| | - Flavia Zuber
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biointerfaces, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Zhihui Zeng
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Cellulose & Wood Materials, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland
| | - René M Rossi
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Katharina Maniura-Weber
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biointerfaces, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Qun Ren
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biointerfaces, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
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10
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Müller A, Fessele C, Zuber F, Rottmar M, Maniura-Weber K, Ren Q, Guex AG. Gallium Complex-Functionalized P4HB Fibers: A Trojan Horse to Fight Bacterial Infection. ACS Appl Bio Mater 2021. [DOI: 10.1021/acsabm.0c01221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Adrienne Müller
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Claudia Fessele
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Markus Rottmar
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Anne Géraldine Guex
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
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Zuber F, Chambion B, Gaschet C, Caplet S, Nicolas S, Charrière S, Henry D. Tolerancing and characterization of curved image sensor systems. Appl Opt 2020; 59:8814-8821. [PMID: 33104565 DOI: 10.1364/ao.400950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/05/2020] [Indexed: 06/11/2023]
Abstract
Curved image sensors, not having to correct the field curvature, are considered a relevant solution for improving the vast majority of optical systems. They offer the possibility of designing compact aberration-free optical systems. In this work, we explain the advantage of the curved sensor system using the aberration theory. A complete procedure was developed to produce functional curved sensors and functional prototypes were carried out. This paper focuses on the tolerancing process of curved sensors and its inclusion in optical design. A compact objective prototype designed and produced demonstrates the advantage of curvature and the impact of tolerancing.
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Weishaupt R, Zünd JN, Heuberger L, Zuber F, Faccio G, Robotti F, Ferrari A, Fortunato G, Ren Q, Maniura‐Weber K, Guex AG. Antibacterial, Cytocompatible, Sustainably Sourced: Cellulose Membranes with Bifunctional Peptides for Advanced Wound Dressings. Adv Healthc Mater 2020; 9:e1901850. [PMID: 32159927 DOI: 10.1002/adhm.201901850] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/14/2020] [Accepted: 02/25/2020] [Indexed: 12/14/2022]
Abstract
Progressive antibiotic resistance is a serious condition adding to the challenges associated with skin wound treatment, and antibacterial wound dressings with alternatives to antibiotics are urgently needed. Cellulose-based membranes are increasingly considered as wound dressings, necessitating further functionalization steps. A bifunctional peptide, combining an antimicrobial peptide (AMP) and a cellulose binding peptide (CBP), is designed. AMPs affect bacteria via multiple modes of action, thereby reducing the evolutionary pressure selecting for antibiotic resistance. The bifunctional peptide is successfully immobilized on cellulose membranes of bacterial origin or electrospun fibers of plant-derived cellulose, with tight control over peptide concentrations (0.2 ± 0.1 to 4.6 ± 1.6 µg mm-2 ). With this approach, new materials with antibacterial activity against Staphylococcus aureus (log4 reduction) and Pseudomonas aeruginosa (log1 reduction) are developed. Furthermore, membranes are cytocompatible in cultures of human fibroblasts. Additionally, a cell adhesive CBP-RGD peptide is designed and immobilized on membranes, inducing a 2.2-fold increased cell spreading compared to pristine cellulose. The versatile concept provides a toolbox for the functionalization of cellulose membranes of different origins and architectures with a broad choice in peptides. Functionalization in tris-buffered saline avoids further purification steps, allowing for translational research and multiple applications outside the field of wound dressings.
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Affiliation(s)
- Ramon Weishaupt
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Janina N. Zünd
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Lukas Heuberger
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Flavia Zuber
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Greta Faccio
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Francesco Robotti
- Laboratory of Thermodynamics in Emerging TechnologiesDepartment of Mechanical and Process EngineeringETH Zurich Sonneggstrasse 3 Zurich 8092 Switzerland
| | - Aldo Ferrari
- EmpaSwiss Federal Laboratories for Material Science and TechnologiesLaboratory for Experimental Continuum Mechanics Überlandstrasse 129 Dübendorf 8600 Switzerland
| | - Giuseppino Fortunato
- EmpaSwiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biomimetic Membranes and Textiles Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Qun Ren
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Katharina Maniura‐Weber
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
| | - Anne Géraldine Guex
- Empa Swiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biointerfaces Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
- EmpaSwiss Federal Laboratories for Materials Science and TechnologyLaboratory for Biomimetic Membranes and Textiles Lerchenfeldstrasse 5 St. Gallen 9014 Switzerland
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Wu S, Altenried S, Zogg A, Zuber F, Maniura-Weber K, Ren Q. Role of the Surface Nanoscale Roughness of Stainless Steel on Bacterial Adhesion and Microcolony Formation. ACS Omega 2018; 3:6456-6464. [PMID: 30023948 PMCID: PMC6045408 DOI: 10.1021/acsomega.8b00769] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 05/28/2018] [Indexed: 05/25/2023]
Abstract
Hospital-acquired infections can cause serious complications and are a severe problem because of the increased emergence of antibiotic-resistant bacteria. Biophysical modification of the material surfaces to prevent or reduce bacteria adhesion is an attractive alternative to antibiotic treatment. Since stainless steel is a widely used material for implants and in hospital settings, in this work, we used stainless steel to investigate the effect of the material surface topographies on bacterial adhesion and early biofilm formation. Stainless steel samples with different surface roughnesses Rq in a range of 217.9-56.6 nm (Ra in a range of 172.5-45.2 nm) were fabricated via electropolishing and compared for adhesion of bacterial pathogens Pseudomonas aeruginosa and Staphylococcus aureus. It was found that the number of viable cells on the untreated rough surface was at least 10-fold lower than those on the electropolished surfaces after 4 h of incubation time for P. aeruginosa and 15-fold lower for S. aureus. Fluorescence images and scanning electron microscopy images revealed that the bacterial cells tend to adhere individually as single cells on untreated rough surfaces. In contrast, clusters of the bacterial cells (microcolonies) were observed on electropolished smooth surfaces. Our study demonstrates that nanoscale surface roughness can play an important role in restraining bacterial adhesion and formation of microcolonies.
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Affiliation(s)
- Songmei Wu
- School
of Science, Beijing Jiaotong University, No. 3 Shangyuancun, Haidian District, Beijing 100044, P. R. China
| | - Stefanie Altenried
- Laboratory
for Biointerfaces, Empa, Swiss Federal Laboratories
for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Andi Zogg
- HESS
Medizintechnik AG, Grabenstrasse
14, 8865 Bilten, Switzerland
| | - Flavia Zuber
- Laboratory
for Biointerfaces, Empa, Swiss Federal Laboratories
for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Katharina Maniura-Weber
- Laboratory
for Biointerfaces, Empa, Swiss Federal Laboratories
for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Qun Ren
- Laboratory
for Biointerfaces, Empa, Swiss Federal Laboratories
for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
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Wu S, Zuber F, Maniura-Weber K, Brugger J, Ren Q. Nanostructured surface topographies have an effect on bactericidal activity. J Nanobiotechnology 2018; 16:20. [PMID: 29490703 PMCID: PMC5830064 DOI: 10.1186/s12951-018-0347-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/22/2018] [Indexed: 01/16/2023] Open
Abstract
Background Due to the increased emergence of antimicrobial resistance, alternatives to minimize the usage of antibiotics become attractive solutions. Biophysical manipulation of material surface topography to prevent bacterial adhesion is one promising approach. To this end, it is essential to understand the relationship between surface topographical features and bactericidal properties in order to develop antibacterial surfaces. Results In this work a systematic study of topographical effects on bactericidal activity of nanostructured surfaces is presented. Nanostructured Ormostamp polymer surfaces are fabricated by nano-replication technology using nanoporous templates resulting in 80-nm diameter nanopillars. Six Ormostamp surfaces with nanopillar arrays of various nanopillar densities and heights are obtained by modifying the nanoporous template. The surface roughness ranges from 3.1 to 39.1 nm for the different pillar area parameters. A Gram-positive bacterium, Staphylococcus aureus, is used as the model bacterial strain. An average pillar density at ~ 40 pillars μm−2 with surface roughness of 39.1 nm possesses the highest bactericidal efficiency being close to 100% compared with 20% of the flat control samples. High density structures at ~ 70 pillars μm−2 and low density structures at < 20 pillars μm−2 with surface roughness smaller than 20 nm reduce the bactericidal efficiency to almost the level of the control samples. Conclusion The results obtained here suggests that the topographical effects including pillar density and pillar height inhomogeneity may have significant impacts on adhering pattern and stretching degree of bacterial cell membrane. A biophysical model is prepared to interpret the morphological changes of bacteria on these nanostructures. Electronic supplementary material The online version of this article (10.1186/s12951-018-0347-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Songmei Wu
- School of Science, Beijing Jiaotong University, No. 3 Shangyuancun, Haidian District, Beijing, 100044, People's Republic of China.
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland
| | - Juergen Brugger
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne, Station 17, 1015, Lausanne, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.
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Ertem E, Gutt B, Zuber F, Allegri S, Le Ouay B, Mefti S, Formentin K, Stellacci F, Ren Q. Core-Shell Silver Nanoparticles in Endodontic Disinfection Solutions Enable Long-Term Antimicrobial Effect on Oral Biofilms. ACS Appl Mater Interfaces 2017; 9:34762-34772. [PMID: 28922597 DOI: 10.1021/acsami.7b13929] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
To achieve effective long-term disinfection of the root canals, we synthesized core-shell silver nanoparticles (AgNPs@SiO2) and used them to develop two irrigation solutions containing sodium phytate (SP) and ethylene glycol-bis(β-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA), respectively. Ex vivo studies with instrumented root canals revealed that the developed irrigation solutions can effectively remove the smear layer from the dentinal surfaces. Further in vitro experiments with single- and multispecies biofilms demonstrated for the first time that AgNPs@SiO2-based irrigation solutions possess excellent antimicrobial activities for at least 7 days, whereas the bare AgNPs lose the activity almost immediately and do not show any antibacterial activity after 2 days. The long-term antimicrobial activity exhibited by AgNPs@SiO2 solutions can be attributed to the sustainable availability of soluble silver, even after 7 days. Both solutions showed lower cytotoxicity toward human gingival fibroblasts compared to the conventionally used solution (3% NaOCl and 17% EDTA). Irrigation solutions containing AgNP@SiO2 may therefore be highly promising for applications needing a long-term antimicrobial effect.
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Affiliation(s)
- Elif Ertem
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH 1015, Switzerland
| | - Beatrice Gutt
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology , St. Gallen CH 9014, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology , St. Gallen CH 9014, Switzerland
| | - Sergio Allegri
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH 1015, Switzerland
| | - Benjamin Le Ouay
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University , Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Selma Mefti
- Dentsply Sirona , Ballaigues CH 1338, Switzerland
| | | | - Francesco Stellacci
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Lausanne CH 1015, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology , St. Gallen CH 9014, Switzerland
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Abstract
We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was <1% of that from flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.
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Affiliation(s)
- Songmei Wu
- School of Science, Beijing Jiaotong University, No. 3 Shangyuancun, Haidian District, Beijing, 100044, P. R. China. and Microsystems Laboratory, École Polytechnique Fédérale de Lausanne, Station 17, 1015 Lausanne, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
| | - Juergen Brugger
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne, Station 17, 1015 Lausanne, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
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Lattuada M, Ren Q, Zuber F, Galli M, Bohmer N, Matter MT, Wichser A, Bertazzo S, Pier GB, Herrmann IK. Theranostic body fluid cleansing: rationally designed magnetic particles enable capturing and detection of bacterial pathogens. J Mater Chem B 2016; 4:7080-7086. [DOI: 10.1039/c6tb01272h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We show theoretical and experimental considerations on bacteria capturing and enrichment via magnetic separation enabling integrated diagnosis and treatment of blood stream infections.
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Affiliation(s)
- M. Lattuada
- Adolphe Merkle Institute
- University of Fribourg
- Fribourg
- Switzerland
| | - Q. Ren
- Department Materials Meet Life
- Swiss Federal Laboratories for Materials Science and Technology (Empa)
- 9014 St. Gallen
- Switzerland
| | - F. Zuber
- Department Materials Meet Life
- Swiss Federal Laboratories for Materials Science and Technology (Empa)
- 9014 St. Gallen
- Switzerland
| | - M. Galli
- Dipartimento di Chimica
- Università degli Studi di Milano
- 20133 Milano
- Italy
| | - N. Bohmer
- Department Materials Meet Life
- Swiss Federal Laboratories for Materials Science and Technology (Empa)
- 9014 St. Gallen
- Switzerland
| | - M. T. Matter
- Department Materials Meet Life
- Swiss Federal Laboratories for Materials Science and Technology (Empa)
- 9014 St. Gallen
- Switzerland
| | - A. Wichser
- Department Materials Meet Life
- Swiss Federal Laboratories for Materials Science and Technology (Empa)
- 9014 St. Gallen
- Switzerland
| | - S. Bertazzo
- Department of Medical Physics and Biomedical Engineering
- University College London
- Malet Place Engineering Building
- London
- UK
| | - G. B. Pier
- Brigham and Women's Hospital
- Harvard Medical School
- Boston
- USA
| | - I. K. Herrmann
- Department Materials Meet Life
- Swiss Federal Laboratories for Materials Science and Technology (Empa)
- 9014 St. Gallen
- Switzerland
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André S, Zuber F, Remize F. Thermophilic spore-forming bacteria isolated from spoiled canned food and their heat resistance. Results of a French ten-year survey. Int J Food Microbiol 2013; 165:134-43. [DOI: 10.1016/j.ijfoodmicro.2013.04.019] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 11/25/2022]
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André S, Hédin S, Remize F, Zuber F. Evaluation of peracetic acid sanitizers efficiency against spores isolated from spoiled cans in suspension and on stainless steel surfaces. J Food Prot 2012; 75:371-5. [PMID: 22289600 DOI: 10.4315/0362-028x.jfp-11-329] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study was to determine the inactivation effect of industrial formulations of peracetic acid biocides on bacterial spores adhering to stainless steel surfaces. A standardized protocol was used to validate biocide activity against spores in suspension. To validate sporicidal activity under practical conditions, we developed an additional protocol to simulate industrial sanitization of stainless steel surfaces with a foam sanitizer. Spores of three spore-forming bacteria, Clostridium sporogenes PA3679, Geobacillus stearothermophilus, and Moorella thermoacetica/thermoautotrophica, were sprayed onto stainless steel as bioaerosols. Sporicidal activity was high against the C. sporogenes spore suspension, with more than 5 log CFU ml(-1) destroyed at all liquid biocide contact times. Sporicidal activity also was high against G. stearothermophilus and M. thermoacetica/thermoautotrophica spores after 30 min of contact, but we found no population reduction at the 5-min contact time for the highest sporicide concentration tested. The foam biocide effectively inactivated C. sporogenes spores adhered to stainless steel but had a reduced decontamination effect on other species. For G. stearothermophilus spores, sanitization with the foam sporicide was more efficient on horizontal steel than on vertical steel, but foam sanitization was ineffective against M. thermoacetica/thermoautotrophica whatever the position. These results highlight that decontamination efficiency may differ depending on whether spores are suspended in an aqueous solution or adhered to a stainless steel surface. Biocide efficiency must be validated using relevant protocols and bacteria representative of the microbiological challenges and issues affecting each food industry.
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Affiliation(s)
- S André
- Centre Technique de la Conservation des Produits Agricoles, Site Agroparc, ZA de l'aéroport, BP 21 203, F-84 911 Avignon cedex 9, France.
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Abstract
The H-NS protein is a major component of the bacterial nucleoid and plays a crucial role in the global gene regulation of enteric bacteria. Although H-NS does not exhibit a high DNA sequence specificity, a number of H-NS-responsive promoters have been shown to contain regions of intrinsic DNA curvature located either upstream or downstream of the transcription start point. We have studied H-NS binding to DNA and in vitro transcriptional regulation by H-NS at several synthetic promoters with or without curved sequences inserted upstream of the Pribnow box. We show how such inserts determine the final organization of H-NS-containing nucleoprotein complexes and how this affects transcription. We refine a two-step mechanism for the constitution of H-NS assemblies that are efficient in regulation.
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Affiliation(s)
- S Rimsky
- Unité de Physicochimie des Macromolécules Biologiques, URA 1773 du Centre National de la Recherche Scientifique, Institut Pasteur, F-75724 Paris Cedex 15, France.
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Zuber F, Kotlarz D, Rimsky S, Buc H. Modulated expression of promoters containing upstream curved DNA sequences by the Escherichia coli nucleoid protein H-NS. Mol Microbiol 1994; 12:231-40. [PMID: 8057848 DOI: 10.1111/j.1365-2958.1994.tb01012.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Replacement of the CRP-binding site of the gal control region by curved sequences can lead to the restoration of promoter strength in vivo. One curved sequence called 5A6A, however, failed to do so. The gene hns exerts a strong negative control on the resulting 5A6A gal promoter as well as on the distant bla promoter, specifically in a 5A6A gal context. The product of this gene, H-NS, displays a better affinity for this particular insert compared to other curved sequences. Mechanisms by which H-NS may repress promoters both at short and long distances from a favoured binding site are discussed.
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Affiliation(s)
- F Zuber
- Unité de Physicochimie des Macromolécules Biologiques (URA 1149 du CNRS), Institut Pasteur, Paris, France
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Affiliation(s)
- S. Isobe
- ; Food Engineering Laboratory; National Food Research Institute; 2-1-2 Kannondai, Tsukuba Ibaraki 305 Japan
| | - F. Zuber
- ; Food Engineering Laboratory; National Food Research Institute; 2-1-2 Kannondai, Tsukuba Ibaraki 305 Japan
| | - K. Uemura
- ; Food Engineering Laboratory; National Food Research Institute; 2-1-2 Kannondai, Tsukuba Ibaraki 305 Japan
| | - A. Noguchi
- ; Food Engineering Laboratory; National Food Research Institute; 2-1-2 Kannondai, Tsukuba Ibaraki 305 Japan
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